Sir Ian's defiant words came in his first speech since the controversial anti-terror raid in East London.

He repeated the Met's apology for hurt caused by the Forest Gate raid which involved 250 officers, and in which a man, subsequently freed, was shot.

Sir Ian said he could not comment on the raid, or on leaked reports about the Menezes shooting last July.

'Harm, hurt and disruption'

Abul Koyair, 20, and his injured brother Mohammed Abdulkahar, 23, were arrested during the high profile raid on their Forest Gate home earlier this month.

They spent several days in custody but later were released without charge. After their release the Metropolitan Police apologised.

In introductory comments to his speech Sir Ian said: "I am not going to respond to the acres of print about Stockwell (where Jean Charles De Menezes was shot) and Forest Gate other than to say two things.

We actually have people, whatever happened in Forest Gate, who are prepared to go into those premises, knowing what happened in Madrid, where many of the police officers were killed

"First to repeat the apology of the Metropolitan Police for the harm and the hurt and the disruption but to reiterate that we will continue to protect public safety wherever credible intelligence requires it.

"Second, the Metropolitan Police does not comment on leaked documents, does not comment on allegations into which the IPCC (Independent Police Complaints Commission) are inquiring to which I and other senior officers have not yet had the opportunity to refute, or to a situation where the family involved can give a press conference but the police are restrained from providing and alternative account."

"We will give these accounts in due course.

"But in the meantime, to paraphrase another great American, Mark Twain, on reading his obituary, accounts of my demise are premature."

Unarmed service

The Forest Gate affair and last year's shooting dead by police of innocent Brazilian man Jean Charles de Menezes have resulted in calls for Sir Ian's resignation.

Sir Ian said people should be "incredibly grateful" that Britain had one of only two unarmed services in the world, with people "prepared to face guns on the streets of London with no weapon".

New Zealand was the other unarmed force, but with respect, he said, Auckland was "not Hackney" or Haringey.

"We actually have people, whatever happened in Forest Gate, who are prepared to go into those premises, knowing what happened in another city called Madrid, where, when they went in, many of the police officers were killed," he said.

"We should be very proud of them."

I don't want one force that is nice and another that turns up in darkened vans and balaclavas, because they are not separate

Sir Ian Blair

Earlier this week Conservative shadow home affairs secretary David Davis said Sir Ian's future had to be resolved with the commissioner being exonerated or replaced.

Sir Ian's speech in central London was on counter-terrorism and community policing.

He said many commentators on policing were focusing on the "wrong problem" but he could not comment beyond his apology.

He said he would argue fiercely against splitting the counter-terrorism effort from local policing, adding that it was the community that provided the "eyes and ears" of the Metropolitan Police.

"I don't want one force that is nice and does all the local policing and another that turns up in darkened vans and balaclavas, because they are not separate," he said.

The conference, organised by think-tank Politeia, is entitled Conquering Crime and Tackling Terrorism: Is there a special relationship?, and will look at a range of issues but will focus on whether there has been a loss of public confidence in the police.

The Centre for Security Policy in Washington and the Manhattan Institute for Policy Research in New York are jointly involved in the central London conference which is being held at the British Academy.